Renewed Measurements of Muon’s Magnetism Could Open Door to New Physics
Published:02 Feb.2018    Source:Science
This week, physicists picked up an old quest for new physics. A team of 190 researchers at Fermi National Accelerator Laboratory (Fermilab) in Batavia, Illinois, began measuring to exquisite precision the magnetism of a fleeting particle called the muon. They hope to firm up tantalizing hints from an earlier incarnation of the experiment, which suggested that the particle is ever so slightly more magnetic than predicted by the prevailing standard model of particle physics. That would give researchers something they have desired for decades: proof of physics beyond the standard model.
 
The muon is a heavier, unstable cousin of the electron. Because it is charged, it will circle in a magnetic field. Each muon is also magnetized like a miniature bar magnet. Place a muon in a magnetic field perpendicular to the orientation of its magnetization, and its magnetic polarity will turn, or precess, just like a twirling compass needle.